This invention relates to the field of digital imaging; and more particularly, it relates to methods for generating a scaled replica of a digital input image. Such a scaled replica may be a magnified replica or a demagnified replica of the input image.
A particular use for the present method occurs in electronic recognition systems. With one type of electronic recognition system, a person can either be granted access or denied access to a secure area based on whether or not an image of the person's face is electronically recognized by the system. Also, with another type of electronic recognition system, various components for a product can be selected or rejected by a robotic arm based on whether or not an image of the component is recognized by the system.
In all of the above applications, a key task which needs to be performed as part of the recognition process is that two images must be correlated. One of these images is the image of an unknown object which the system is trying to recognize, and the other image is of a known object which the system uses as a reference. If the correlation between the two images exceeds a predetermined threshold value, then the unknown object is recognized.
However, before the two images can be correlated, they must be scaled such that they have substantially the same magnification. Otherwise, if one image is larger than the other image, a pixel-by-pixel correlation of the two images will never exceed the threshold value.
Accordingly, a primary object of the present invention is to provide a novel method by which a scaled replica of a digital input image can be generated.